PROJECT SUMMARY Young children are dependent on their parents to create family environments that support healthy weight, yet many parents do not consistently parent in ways that protect their children from obesity. Further, several interventions to improve parenting as a means to address early childhood obesity have struggled with parent engagement and adherence. In adults, poor self-regulation, or limitations in an individuals' capacity to regulate emotions, thoughts, and behavior, is a robust, yet modifiable, risk factor for obesity. Poor self-regulation may similarly interfere with parents' ability to parent in ways that support their children's healthy weight, but there are no robust data to directly support this conjecture. Further, while improving children's self-regulation has been identified as a promising method to address childhood obesity, we do not currently understand how parent and child self-regulation work together to impact children's growth. This lack of information precludes us from identifying whether targeting child self-regulation alone, parent self-regulation alone, or both together, may be the most effective means to prevent or treat childhood obesity. Our long-term goal is to identify strategies to sustainably improve parents' use of practices that support children's healthy weight. The objective of this study is to identify the interrelationships between mothers' self-regulation, their weight-related parenting practices, child self-regulation, and child adiposity from ages 3 through 5, a critical period for preventing the onset of long-term obesity. Our central hypothesis is that poor self-regulation impedes mothers' engagement in parenting practices that support children's healthy weight, leading to excessive gains in adiposity among young children. We also expect that in families where both mothers and children have poor self-regulation, mothers have even greater difficulty engaging in effective weight-related parenting, and children will experience the most rapid gains in adiposity. To test this central hypothesis, we will conduct a prospective cohort study enrolling a socio-demographically diverse sample of 300 mother/child dyads, collecting data 3 times over 2.5 years to address the following specific aims: (1) Identify relationships between mothers' self-regulation and weight-related parenting practices, (2) Identify relationships between mothers' self-regulation and changes in child adiposity, and (3) Identify how child self-regulation modifies relationships between mothers' self- regulation, weight-related parenting, and child adiposity. This project is conceptually innovative in its focus on mothers' self-regulation, its recognition of the dyadic interactions between mothers and children, and the use of rigorous methods to measure self-regulation and parenting. This research is significant because it will elucidate when, how, and among whom deficits in mothers' self-regulation contribute to their young children's obesity risk. There are known strategies to improve self-regulation and enhance behavior change among adults with poor self-regulation. Findings will provide essential guidance for the development of novel intervention approaches to target mothers' self-regulation as a mechanism to prevent and treat childhood obesity.